The present invention relates to a fire extinguishing method as defined in the preamble of claim 1, especially for spaces intended for the storage, maintenance, testing etc. of aircraft, such as hangars, in which method a fire extinguishing medium, especially a liquid mist, is sprayed, via at least one first nozzle in an area, seen in a vertical direction, between an object to be protected/extinguished, such as an aircraft, and the floor of the space or equivalent.
The invention also relates to a fire extinguishing apparatus as defined in the preamble of claim 12, especially for spaces intended for the storage, maintenance, testing etc. of aircraft, such as hangars, said apparatus comprising at least one first nozzle, which, when activated, is directed to spray an extinguishing medium, especially a liquid mist, in the area, seen in a vertical direction, between an object to be protected/extinguished, such as an aircraft, and the floor of the storage space, and means for supplying an extinguishing medium to the afore-said nozzles.
Fire extinguishing systems of spaces, such as various hangars, intended for the storage, maintenance, testing etc. of aircraft, such as airplanes, are very important as a means of protecting the valuable craft from a possible fire. Fires particularly difficult to extinguish are those occurring e.g. under an airplane, especially under its wing. So far, fire extinguishing systems used in hangars typically comprise nozzles installed above the object and/or in the floor, through which is sprayed a fire extinguishing medium, especially extinguishing foam. In such systems, the aim is to fill the entire space between the aircraft and the floor with foam. At the same time, however, efforts are made to prevent adverse effects of the foam on the aircraft. A disadvantage with systems using extinguishing foam is especially the cleaning work required after their application, especially on aircraft. Moreover, to allow such a system to be used, the space in which extinguishing foam is to be applied has to be evacuated before the system is triggered into action, which thus introduces a delay between the detection of fire and activation of the extinguishing system. Fire extinguishing systems using so-called film-forming foam are also known. In these systems, the extinguishing medium forms a film on the surface of objects. One of the disadvantages of these is that they typically have highly corrosive properties, which may damage the object to be protected. Moreover, their effectiveness is limited to only given types of fire. In addition, prior-art fire extinguishing systems are difficult to provide in the spaces to be protected without said systems interfering with other activities carried on in them.
In fire-fighting technology, extinguishing systems based on water mist are also known, the use of which typically does not involve the disadvantages of systems using extinguishing foam.